Compilare: user.c:4:1: warning: data definition has no type or storage class [enabled by default] a[50001]; ^ user.c:4:1: warning: type defaults to ‘int’ in declaration of ‘a’ [enabled by default] user.c: In function ‘main’: user.c:9:51: warning: unused variable ‘sn’ [-Wunused-variable] int n,k,x,i,p=1,sc,umax,pmax,smax=-2147483646,sn; ^ user.c:10:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d\n",&n,&k); ^ user.c:13:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&x); ^